Chain saw sharpening device



June 30, 1953 B. EvANoFF 2,643,553

CHAIN sm SHARPENING DEVICE Filled Feb. 2, 1952 2 Sheets-Sheet 1 I N V EN TOR. @OREECEEVA/YFF June 30, A1953 B'." EvANor-F CHAIN SAW SHARPENING DEVICE Filed Feb. 2. 1952 2 Sheets-Sheet 2 INVENTOR. 5025565 TVH/V05C www` Patented June 30, 1953 UNITED STATES PATENT OFFICE CHAIN SAW SHARPENING DEVICE Boreece Evanoil, Oak Creek, Colo.

Application February 2, 1952, Serial No. 269,662

Claims. (Cl. 76-37) This invention relates to a tooth-sharpening device for chain saws, 4and has for its principal object the provision of a simple, easily used, portable device by means ci which the teeth of a conventional chain saw may be quickly, easily, and accurately sharpened. v

Another object is to so construct the device that it can be used with any type of power available, and which, if necessary, can be used for hand sharpening.

A further object is to provide a gauge means for saw sharpening devices which sharpenv alternating right and left-hand saw vteeth at the proper cutting angle for highly ecient sawing uses.

Other objects and advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and eiiiciency. These will become more apparent from the iollowing description. v

in the following detailed description of the invention, reference is had to the accompanying drawing which forms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

Fig. l is a top plan view of the improved saw sharpening device, illustrating it in two different positions upon the blade ci a conventional chain saw;

Fig. 2 is a iront view thereof chain saw;

Fig. 3 is a longitudinal section through the improved Sharpener, taken on the line 3--3, Fig. l;

Fig. 4 is a detail section, taken on the line Ci-55. Fig. l, illustrating an abrasive arbor em.- plcyed in the improved sharpening device;

Fig. 5 is a cross-section, taken on the line 5-5, Fig. l; and

Fig. 6 is a detail section, taken on the line i---, Fig. l.

in the drawing the blade plate of'a conventional. chain saw is indicated at il] having the usual edge groove for guiding the links of a conventional saw chain Il, from which right-hand saw teeth l2 and left-hand saw teeth I3 alternately project. Raker teeth Il! project from the chain intermediate the right and left-hand saw teeth l2 and i3.

The improved saw sharpening device employs a triangular gauge plate I5, the front or base edge ot which is cut and folded downwardly adjacent the diagonal sides of the gauge plate I5 to form two rear flange plates It. A T-shaped neck portion Il is formed on the gauge plate i5 intermediate the two rear iiange plates I6 in place on the structions.

the gauge plate.

and extends forwardly of the latter. The T-head on the T-shaped neck portion is folded downwardly at right angles to the plate I5 parallel to and spaced from the iiange plates IB to form a front flange plate I8.

The gauge plate I5 is designed to support an elongated mandrel bearing tube I9 provided, with a threaded pivot stud 2U which extends downwardly through any desired one of a plurality of pivot holes 2 I, which are formed in the gauge plate I 5 on the center line and adjacent the apex thereof. The pivot stud 20 is secured in place by means of a suitable retaining nut 22. The bearing tube I9 can be swung about the axis of the stud 20 to positions substantially parallel to the two inclined side edges of the triangular gauge plate I5.

The tube i9 is held in either of its angular positions by means of a leaf-type retaining spring 23 having arcuately bent extremities 2li beneath which the bearing tube snaps into position. The leaf spring 23 is mounted on a spacing block 25 of predetermined length. The spring and block are secured on the gauge plate I5 in any desired manner, such as by means of suitable mounting screws 25. The bearing tube I3 is constantly urged toward the spacing block 25 by means of a tension spring 2l, one extremity of which is hooked about the tube I9, and the other extremity of which is mounted on a spring stud 23 projecting upwardly from the plate I5.

A mandrel 29 extends throughout the length of the tube I9 and is rotatable therein. One extremity of the mandrel is provided with an. abrasive cylinder or round le 30. The other extremity is threaded, as shown at 3|, or otherwise arranged to receive a coupling 32 of a flexible shaft 33, as is usual in flexible shaft con- The mandrel 29 is prevented from moving endwise in the tube I9 by means 0i a U-shaped spring clip 34 which extends through a notch 35 in top of the tube i9 to engage in either one of two circumferential grooves 36 formed in the mandrel.

An adjusting screw block 3l is mounted on a pivot stud 38 positioned in the neck portion il of An adjusting screw 3S extends longitudinally through the block 3l and may be locked in any desired position therein by means of a set screw 40. The device may be, if desired, securely locked to the chain saw and blade plate l I by means Vof a clamp screw lll mounted on the front ange plate I8 and adapted to clamp against the blade platel. The exible shaft 33 may be rotated by hand or may be connected to any suitable power source.

In use, the neck portion I1 of the gauge plate is placed over the chain saw II, with the rear ange plates engaging one face of the chain and the blade plate I0, and the front flange plate I8 engaging the opposite face of the chain and blade plate. Let us assume that the gauge plate is positioned on the right side of the saw between one of the left-hand teeth I3 and one of the raker teeth I4, as shown in solid line in Fig. 1. The adjusting screw 39 bears against the back of the tooth I3, and this screw is adjusted so as to bring the round rile 30 lightly against the tooth I3 and to force the bearing tube against the action of the spring 21 and slightly away from the spacer block 25. The adjusting screw 39 is now locked in the adjusted position and rotation is imparted to the mandrel 29 and'le 39 to grind away the cutting face of the tooth on an angle corresponding to the angle of the bearing tube I9.

The grinding continues until the bearing tube I9 comes into contact with the spacer block, which prevents the spring 21 from imparting further angular movement to the bearing tube. The gauge plate is then moved successively rearwardly of each left-hand tooth until all of the latter teeth have been sharpened upon a common uniform angle. y

The gauge plate I is now moved to a position on the left-hand side of the chain saw, as shown in broken line in Fig. 1, so as t0 be positioned rearwardly of the right-hand teeth thereon. The adjusting screw block 31 is rotated 180 vabout its pivot stud 38 so that the adjusting screw 39 will contact the back of the right-hand teeth I2, and the bearing tube is swung around its pivot stud 20 to the opposite side of the gauge plate and under the opposite side of the gauge plate and under the opposite extremity of the leaf spring 23, where it will be acted upon by the spring 21, as shown in broken line in Fig. 1. The le 3u is now rotated to sharpen the entering edge of the right-hand tooth I2 and is moved from tooth to tooth until all of the right-hand teeth have been sharpened.

It will be noted that the amount of grinding is limited by the positionl of the adjusting screw 39, as this regulates the position of the saw blade in the device. When the adjusting screw is once set, the angle of cut and the amount of metal removed on all teeth will be uniform so as to produce a sharp, rapid sawing action.

The angle at which the teeth are ground may be increased, if desired, by moving the stud 25 of the bearing tube to one of the holes ZI closer to the saw, and the round le can be retracted into the bearing tube to accommodate the closer position by releasing the spring clip 34 and moving the mandrel outwardly until the clip may be re-engaged in the closer circumferential groove 35.

The device may be used as a gauge for hand sharpening by simply removing the ilexible shaft and the spring clip. The mandrel may then be reciprocated by hand to cause the round le to sharpen the teeth on the proper angle.

While a specic form of the improvement has been described and illustrated herein, it is to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention.

Having thus described the invention, what is claimed and described secured by Letters Patent is:

1. A saw sharpening device comprising; a gauge plate; an inside flange extending downwardly from said gauge plate to engage one side of said saw; an outside flange extending downwardly from said gauge plate to engage the other side of said saw; an adjusting screw mounted on said gauge plate over said saw and positioned to engage a tooth of the latter; a rotary saw sharpening member pivotally mounted on said gauge plate and adapted to engage the other side of said tooth; a spacing member mounted on said gauge plate; a spring urging said sharpening member toward said spacing member; and a leaf spring mounted on said spacing member and resiliently engaging said sharpening member for retaining the latter in place. y

2. A saw sharpening device as described in claim 1 in which the leaf spring projects oppositely outward from -both extremities of the spacing member so as to engage said sharpening device when the latter is swung to either side of said gauge-plate.

3. A saw sharpening device as described in claim 2 in which the sharpening member comprises an elongated tubular bearing; a pivot stud projecting downwardly from said bearing through a pivot hole in said gauge plate; a mandrel rotatably mounted in said bearing; a cylindrical abrasive member on the forward extremity of said mandrel positioned to engage said tooth; and means for rotating said mandrel.

4. A saw sharpening device as described in claim 3 having a plurality of spaced-apart, circumferential grooves formed in said mandrel; and a resilient U-shaped retainer positioned exteriorally of said tubular bearing and engaging in a selected one of said grooves through an opening in said bearing.

5. A chain saw sharpening device comprising: a base plate; means for attaching said base plate to said saw so that it will project in a plane at right angles to the plane of said saw adjacent the teeth thereof; a tubular bearing member; a pivot stud projecting downwardly from said bearing member through a pivot hole in said gauge plate; an adjusting screw block; an adjusting screw threaded through said block and positioned to engage one side of a tooth of said saw; a rotatable mandrel in said bearing member; a cylindrical abrasive member on the extremity of said mandrel positioned to engage the other side of said tooth; spring means urging said abrasive member toward said tooth; and stop means positioned to stop the movement of said bearing member at a predetermined point, said bearing member being movable to either side of said gauge plate, and said adjusting screw block being rotatable on and in the plane of said plate so that the adjusting lsrrew may Contact a tooth at either side of said ook.

BOREECE EVANOFF'.

References Cited in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS Country Date Germany Jan. 26, 1939 Number Number 

